Eating for a high metabolism

I'm 19, 5' 9", 134 lbs., and practically only lean muscle (ex XC runner).

I just started lifting with a buddy who's almost broken 200 lbs. and he's an inch shorter than me. He's gotten all of his information from this site over the last 2-3 years and he's gone from my size to a mini ox.

After he told me to check this site out I noticed that there were certain eating habits I'd never been aware of. I'm currently trying to set up a schedule around work so I can get my 6 meals in every day. I'm simply looking to put on some mass right now and worrying about sculpting it to look pretty later.

My problem is that, in 4 years, I have never gained nor lost a single pound. I'm looking for help so I'm being upfront and honest. My figure has become a little more athletic from running... but no weight change. I've always been like this and figure my metabolism probably runs like a race horse (simply my opinion).

If that's the case, should I be increasing any kinds of foods I'm taking in? I'm a little lost simply because I don't know how much that will affect my results.

eat a great breakfast after workout when consuming protein try mixing with 1% milk ot ta  do the trick, and a milk shake b4 bed

Bench 290       

SKWat 395

Dead lift 325

bod fat around 12

6 ft flat

Chocolate Milk!